Hi Ed,
How much are you selling your 375HE brass for? I managed to sell my Weatherby so that will get things going on a build. Planning on the Bat-L action and Bartlein barrel with Lester Bruno doing the build.

For those of you that might have missed it, Applied Ballistics (AB) recently announced a new DVD, ELR Shooting with Applied Ballistics: Applied Ballistics' campaign for the 2017 King of 2 Miles competition." [Available at https://store.appliedballisticsllc.c...oductCode=0009 Pre-order pricing still shown.]

I pre-ordered one and received it last week. In watching it today I noted:

1. None of the AB shooters in the video were using anything "special" in the scope and mount department, specifically no TACOMHQ gear. The three team members in the Top 10 were using NT ATACR 7-35x56 scopes. A shot earlier in the DVD showed an Ivey mount on one of the rifles but I was unable to identify it in the actual competition section of the video.
2. At one point the front end of Derek Rogers scope was visible and I noted that he was using a "modifier disk" - I tried my March modifier disk on my 56mm ATACR and it would not fit. For those unfamiliar with such a device, see http://marchoptics.com/accessories . I found no such product on the NF website (at least in the Accessories section).
3. Anyone seriously considering shooting Ko2M - this DVD is well worth the tab.

Modifier disk is extremely convenient. I’ve been using electrical tape for many years. As much as I hate them you could use a butler creak flip cap and a small hole saw. Buy a few put different diameters in there.

Ed: I thought the 416 HSM is to have a rebated rim - down to CT size. That would allow use of the BAT L action (which is available with CT bolt face).

The L is available 2.0" OD, same as the .50 BMG-focused EX, but the L's loading port is only 3.8" long vs the EX at 5.5". If a shooter wanted to load shell-holder-action style (remove the bolt to R&R cartridges), the L that would work just fine.

URSAFacilitator
You can use the factory scope caps and just have someone with a lathe make an opening for you. Jim Ketchum has made me several for the 56mm Nightforce scopes I use.
If I dig them up I will send you one.

For those that missed what Lynn is talking about, my earlier post in this thread mentioned Derek Rogers using a "modifier disk" at the Ko2K. I noted, that while I had a modifier disk for my March scope I could not find one listed on the NF site for their scopes. With that preamble...

Lynn - then I'd have to deal with junk blowing around getting inside (why I close my factory pop-up NF caps when not shooting). I'm looking for a screw-in solution like the March solution that the pop-up lens caps will fit. Did Ketchum machine the older metal NF lens caps or are you talking about their rubber lens caps? If metal, yes, please be so kind as to find and send me one. I'll live with the junk blowing around.

I found a company that supposedly makes what I want BUT their product listing seems to be a one-size-fits-all because they provide only one offering with no way to indicate which scope you have and list several NF scopes as "made to fit" but that have different part numbers for corresponding sunshades for those scopes on the NF site. I've e-mailed their e-mail address because their contact form does not "submit".

All the above noted, in reading about the mirage-reduction capabilities of "modifier disks", I found that different mirage conditions require different size holes/openings in the modifier disks. Some smart person, opportunity knocks - design and market an adjustable-aperture modifier disk. And post on CalGuns to tell us about it. Thanks.

Quote:

Originally Posted by LynnJr

URSAFacilitator
You can use the factory scope caps and just have someone with a lathe make an opening for you. Jim Ketchum has made me several for the 56mm Nightforce scopes I use.
If I dig them up I will send you one.

URSAFacilitator
I will post two pictures showing the modifier discs I use. They are the factory caps that come from Nightforce with the center lathe turned to a given size.
These are threaded with a shoulder and don't vibrate lose so far.
I would think someone with a 3D printer could make them out of plastic and if the shoulder diameter was the right size they would self thread themselves?

Sigstroker - please provide link or at least the word(s) I need to search on. Thanks.

I found a guy that sells mirage caps/modifier disks for NF - http://www.kreativ-solutions.com/mirage-caps.html - his ordering system is not that great, so I strongly suggest you contact him to make sure you get the right version (they are NOT all the same).

Sigstroker - please provide link or at least the word(s) I need to search on. Thanks.

I found a guy that sells mirage caps/modifier disks for NF - http://www.kreativ-solutions.com/mirage-caps.html - his ordering system is not that great, so I strongly suggest you contact him to make sure you get the right version (they are NOT all the same).

the 416 HSM, Its 2" action would do if it had bigger bolt, maybe we can

get them to build one with bigger bolt, but not as big as bmg.

The Barnard P-Cheytac will do and few others, as well as bmg ones .

We are getting set up for making 375 HE sizing dies. Ready soon. Ed

......................

Ed, I'm confused. I think you are saying that the receiver's "raceway" is too small in diameter to accept the BMG-ish case diameter. Correct?

BTW, your 9/3/17 post drawing shows .740 above the extractor groove. The corresponding dim of a .50 BMG is close to .804 (CIP dim P1). Are you trimming .032 off the case wall or "swaging" it inside or a combo or? Thanks.

__________________
ELR Researcher, Endowment Member NRA and Life Member CRPAwww.elr-resources.com
Not a commercial business.
ELR - anything shorter is point blank.

For big long cases our testing is showing that the 416 easier to get powders to work with, less problems ..
Maybe building a target gun,don't have 375 barrel all ready, maybe go 416....

Got sent 5 thick sided sample cases, same OD base as 585/375.416 cases, same belt, just .180" longer,
did a 416 HE, chambered extra barrel , cases stick over 50k. They have about .042" total taper, .021" per
side, when I necked couple to 416. That is a lot of taper , twice the taper of my 416HE...hanging up at 50k..

I could maybe go to 65k with these if we made taper with ..012" - .016" more taper to each side, but that is
no way to build target cases. I'd have to crunch down case shoulder diameter. And would look like 30-30.

And crazy part is, the case has enough brass material to thin up sides and stretch them way out to 4 or
more inches,, They weigh 150 gr more than our 585/375/416,, but with real thick sides they actually
hold less than our 416 HE with thin sides, that is .180" shorter...Our case does 65k ok without sticking..

And we can make super long 4" cases work if we had means to get them built, as we have
15 powders slower than HBMG.Here is pic of thin and thick sided cases, sectioned for comparison.Ed..

Others have sent cases to section and look at, that are built thick sided and they stick also for the folks, If a longer case with about 5 sq in of side surface sticks and don't spring back, the coefficient of friction is about .01 then the pull needed to move it is 2500-3500 lbs..That is for big cases with normal amount of slant to the sides. Ed.

Here is picture of six nyati and gibbs size cases sectioned..5th one is present 585 HE]
and 6th is thick sided version. 1st is 600 OK which essentially nyati basic case left straight, belt added.

In the picture the nyati gma is one we built most of our first 585s on. Before we had factory run.
Reworking made it in size that is now my 585 HE, but that brass had the sides of perfect thickness,
not too thick, but thin without sharp transition my new factory 585s had, they last forever as 585s......

Fourth one is an older nyati case I used to make about 10 of my 585s from ...they had thin sides
and sharp transition, and then I tested these 20 years ago, and they would separate after -4-6 hot loads
as 585s, my factory 585 with right powders as a 585 will get 10 hot loads, and necked down to
416/375 4- 6 hot loads, right powders used, Moderate 577 equivalent, factory 585 at least 20 loads..Ed.

Guy sent thick sided 375 case, next size base diameter up from Nyati.He said,
'Yes I ran them in a ___________ rifle built by ____, the best I
could get was 44000 psi, any more and they were stuck''

Big bore guys. other forums over the years related that trex/african case in 585
size, thick sided cases, stuck when they loaded them over 45k psi.

Another just sent us, thick sided 375, long case, same base OD as our 585 HE,
416 HE, 375 HE, and Mitch's 375 Lethal, and the thick ones stuck over 45k psi.

Now you can fill those cases up, with ultra slow enough powder so they won't
stick, but powder is too slow for max speed. Might get a little more
speed, with thick sides case, but case got to be 4- 4.5 inches long..

. Anyone needing a sectioned case of the ones I made the first of my 585s from,
contact me, if they want to get a general idea of what case side thickness should
be, in Gibbs size cases on up to about trex and 375 VM size case diameter.

Here is pic of our 585 based case next to brand X and thick ones, both have
same sharp, thinner, corner, where transition from heavy angled corner, to the
side, the carbide draw rod could easily be reshaped with diamond wheel,
just by grinding off sharp transition corner. Then sides would be perfect.., .

Here is picture of 416 HE in a Choate target/varmint stock guy is doing,
using long action BSA U9 action.Setting in stock ready to do bedding..Ed

Ed - at one point not too long ago I'd asked you how you (and now these other folks) are measuring the pressure levels you are noting. I can't find that post but am reasonably sure it was not responded to. I'm thinking you are "just" entering barrel, bullet, case, and powder info into QuickLOAD and accepting the pressure value that it generates. Please advise. Thanks.

__________________
ELR Researcher, Endowment Member NRA and Life Member CRPAwww.elr-resources.com
Not a commercial business.
ELR - anything shorter is point blank.

Here is picture of thick 375 case sent to me, with thick sided trex case, and our HE case,
The thick 375 case is .050" bigger OD base, but inside is no bigger than HE cases..
These thick sided 375s stuck when loaded over 44,000 psi....

Got guys asking and I'm doing it, to do my 416 HSM case for BMG actions, so leaving rim same,
as the original bmg rim, so will neck them, fire form to the longer shoulder, like the others.
Base a little bigger, Shoulder same diameter, same 30 degree slant, neck will be same..

The inside of case still has close to same shape and volumn within 3 % as the ones we slimmed down.
Some want to use bmg actions and can't wait for intermediate actions, or already have bmg action.
And they are really getting interested in the complete line of 416 CEB bullets now being done..Ed